As a Shopify developer, it is possible to access the metafields created on the customer account in Shopify POS Lite using the Shopify API.
Firstly, you will need to authenticate your app and request the necessary permissions from the store to access customer information. Then, you can use the Shopify API to access the customer resource and retrieve the metafields for the customer account.
Once you have retrieved the required metafields, you can then use them to create an order using the Shopify API.
For the metafields that contain upload data, you may need to handle them differently. You can use the Asset API to upload files to the store and then link the uploaded asset to the customer's metafield.
It's worth noting that accessing metafields requires the use of the Shopify API, and the API calls will count towards the API call limit. Therefore, it's important to use the API efficiently and avoid making unnecessary API requests.
Overall, with the necessary Shopify API knowledge and experience, it is possible to access the metafields created on the customer account in Shopify POS Lite and use them to create orders.